Sulfo-Cy5 Picolyl Azide

Sulfo-Cy5 Picolyl Azide is a water-soluble Cy5-based azide reagent designed for copper-free click chemistry workflows, enabling rapid, bioorthogonal conjugation to cyclooctyne/DBCO-functionalized biomolecules, affinity ligands, and surfaces. Its sulfonated Cy5 chromophore supports bright far-red fluorescence for labeling and imaging applications, while the picolyl azide functionality provides a robust handle for constructing fluorescent conjugates under mild conditions.

1. Biomolecule Labeling

Sulfo-Cy5 Picolyl Azide is used to generate far-red fluorescent bioconjugates for protein, peptide, and other biomolecule labeling workflows where researchers need a stable fluorescent tag for microscopy and fluorescence-based assays. In practice, it is commonly paired with DBCO- or cyclooctyne-functionalized targets (for example, antibodies, protein scaffolds, or engineered binding proteins) to produce fluorescent conjugates for tracking binding, quantifying conjugation outcomes, and visualizing labeled biomolecules in complex samples.

2. Fluorescence Microscopy Tracing

Sulfo-Cy5 Picolyl Azide supports fluorescence microscopy experiments that benefit from far-red emission to reduce background from common cellular autofluorescence. Researchers use it to stain or trace biomolecule distributions in fixed or prepared samples by first preparing DBCO-functional imaging constructs (such as labeled ligands, targeting reagents, or surface-bound probes) and then performing azide-cyclooctyne click labeling to install the Cy5 fluorophore. The sulfonate-bearing dye format helps maintain aqueous compatibility for staining and wash steps in imaging workflows.

3. Surface Functionalization

Sulfo-Cy5 Picolyl Azide is applied in biomaterials and surface engineering to create Cy5-labeled coatings and functional interfaces for fluorescence readouts. Teams working on hydrogels, nanoparticles, microcarriers, and assay surfaces often incorporate cyclooctyne/DBCO groups onto the material or scaffold and then use Sulfo-Cy5 Picolyl Azide to install the fluorescent reporter via click conjugation. This enables visualization of surface coverage, tracking of material-associated components, and development of fluorescence-based characterization assays for engineered materials.

4. Flow Cytometry Labeling

Sulfo-Cy5 Picolyl Azide is used to prepare far-red flow cytometry labeling reagents that can be detected in standard fluorescence channels compatible with Cy5-like emission. In typical workflows, researchers conjugate the azide dye to DBCO-functional targeting molecules (such as binding reagents or engineered affinity ligands) to generate fluorescent probes for cell-surface or sample-associated labeling. The resulting Cy5 conjugates are then used to quantify labeled populations and compare labeling conditions across experimental groups in fluorescence-activated cell sorting and analytical flow cytometry assays.